Manufacture of filters for cigarettes or similar smokable articles

ABSTRACT

THE INVENTION CONSISTS ESSENTIALLY IN THE USE OF AN EXTENDED SCREEN MEMBER WHICH MOVES IN UNISON WITH THE GARNITURE TAPE OF A CONTINUOUS FILTER ROD FORMING MACHINE AND THROUGH WHICH SCREEN MEMBER GRANULAR OR LIKE LOOSE FILTER MATERIAL IS SHOWERED TO BE GUIDED BY THE SCREEN MEMBER INTO POCKETS FORMED BETWEEN FILTER PLUGS WHICH ARE CARRIED BY AND SPACED APART ALONG THE GARNITURE TAPE.

Nov. 30, 1971 N. w. JACKSON 3,623,404

MANUFACTURE OF FILTERS FOR CIGARETTES 0R SIMILAR SMOKABLE ARTICLES Filed June 13, 1.969 3 Sheets-Sheet l Nov. 30, 1971 N.

MANUFACTURE OF FILTERS FOR CIGARETTES on W. JACKSON SIMILAR SMOKABLE ARTICLES 5 Sheets-Sheet 2 Filed June 13, 1969 f l l i T x b w l .M Q a a I l .5. r Q

Nov. 30, 1971 N. w. JACKSON MANUFACTURE OF FILTERS FOR CIGARETTES OR SIMILAR SMOKABLE ARTICLES 5 Sheets-Sheet 5 Filed June 13, i969 United States Patent 3,623,404 MANUFACTURE OF FILTERS FOR CIGARETTES R SIMILAR SMOKABLE ARTICLES Norman W. Jackson, London, England, assignor to Molins Machine Company Limited, London, England Filed June 13, 1969, Ser. No. 833,020 Claims priority, application Great Britain, June 14, 1968,

28,606/68; Nov. 1, 1968, 51,802/68 Int. Cl. B23d /00 US. Cl. 93-1 C 9 Claims ABSTRACT OF THE DISCLOSURE The invention consists essentially in the use of an extended screen member which moves in unison with the garniture tape of a continuous filter rod forming machine and through which screen member granular or like loose filter material is showered to be guided by the screen member into pockets formed between filter plugs which are carried by and spaced apart along the garniture tape.

This invention relates to improvements in or relating to the manufacture of filters for cigarettes, or similar smokable articles, and is particularly concerned with the production of filter incorporating a granular, powdered or other particulate filtering material (referred to hereinafter for convenience as loose material).

In one known technique for making filters of this type the loose material is incorporated in pockets between stubs of filter material and the whole is enclosed in a paper wrapper. The filters are made in the form of a continuous rod, the paper being formed into a trough with the plugs dispersed at intervals along the trough and then the loose material is introduced into spaces between the plugs within the paper trough and the paper is folded and sealed around the stubs, and lengths of the continuous rod cut off through the stubs to provide filter plugs for combining with tobacco rods to form filter tip cigarettes. In one way of introducing the loose material into spaces between the stubs, a reel having a series of pockets around its circumference is used and is disposed above the rod maker, so that the pockets in the lower part of their travel register with the spaces between the stubs, and in the upper part of their travel they communicate directly with a hopper which supplies each of the pockets with the loose material; thus a measured volume of material is delivered separately to each space. While this apparatus is prefectly satisfactory for many conditions of operation and different types of materials, there are some problems in certain circumstances. For example, it can be difficult to get all the material out of the pocket into the relevant space or accurately to fill the pocket, and it is also difficult to vary the quantity of material which is introduced into the space between the stubs. It is an object of the present invention to provide improvements in the production of filters containing loose material for cigarettes or other smokable articles, and it is particularly concerned with providing improvements in supply of the loose material from a source to a rod like forming device.

According to one aspect of the present invention there is provided a method for manufacturing a continuous filter rod, to provide filters containing loose material for cigarettes or other smokable articles, comprising forming a continuously moving trough of wrapping material, providing stubs of porous filtering material at regular intervals along the trough and introducing controlled amounts of loose filtering material from a bulk supply of such material into the spaces between the plugs, wherein the loose material is caused to fiow continuously at a controlled rate onto a continuously moving screen member which is moved in unison with the rod so that the screen member directs the flow of loose material into each of the spaces in turns.

The loose material being showered downwardly over a fixed length of the screen member so as to embrace several apertures in the screen member at a time and cause the loose material to thus fall into or through the said several apertures simultaneously as they pass beneath the showered material.

The loose material is formed into the said shower by being vibrated on an inclined surface over one edge of which the material is allowed to drop.

The screen may comprise a plurality of interconnected links each of which is shaped to form either by itself or in association with an adjacent link, a pocket designed to temporarily carry a predetermined volume of loose filter material.

An advantage of the method according to the present invention is that the quantity of loose material delivered to each space between adjacent plugs can be varied by varying the feed rate. This is something which can be done quite easily, whereas with the known pocketed wheel it is necessary to change the size of the pockets.

Furthermore with the apparatus according to the present invention the time during which the flow of loose material is submitted to each pocket can be controlled by arranging for loose material which is fed downwardly in a shower to be fed over a distance which embraces several of the said spaces between adjacent plugs, this distance being selected to give desired rate of feed of loose material.

The method of the present invention may be combined with the methods disclosed in United States application Ser. No. 797,435. In that application filter plugs having over-sized diameters are selected so as to increase the useful volume into which the loose filter material can be deposited, the over-sized plugs being then subsequently compressed down to the required diameter after the loose filter material has been deposited between adjacent plugs. Standard diameter or over-sized diameter filter plugs may be employed, the essence of the method being to deform the plugs, prior to the deposition of the loose filter material, so that again the useful volume between adjacent plugs is increased so that more effective filling of the adjacent spaces between the plugs can effected.

The present invention can be used for the introduction of various types of filter material and in particular it can be used for introducing finely divided materials such as powders, or mixtures of powders with larger particles.

How the invention may be carried out will now be described, by way of example only, and with reference to the accompanying drawings, in which:

FIG. 1 is a side elevation, partly in section, of a first cigarette filter making machine incorporating the present invention;

FIG. 2 is a section on the line IIII of FIG. 1;

FIG. 3 is a plan view of part of FIG. 1;

FIG. 4 is a view similar to FIG. 1 of a second machine incorporating the present invention;

FIG. 5 is a section on the line V-V of FIG. 4;

FIG. 6 is a plan view of a part of FIG. 4;

FIG. 7 is a view, similar to FIG. 1 but on an enlarged scale, of a third machine embodying the present invention; and

FIG. 8 is a section on the line VIIIVIII of FIG. 7.

FIGS. l-3

The apparatus comprises a garniture bed 1 which is formed from upper and lower platens and which as a central trough 2 through which a garniture tape 3 carries a continuous web of cigarette paper 4. Stubs 5 of filtering material, such as acetate tow, are spaced at regular intervals along the paper web 2 before the web enters the part of the apparatus shown in the drawing.

Disposed immediately above the trough 2 is a hopper chute 6 down which a loose filtering material 7 is fed, from a bulk store supply at a steady rate by means of suitable conveyors which are vibrated to cause the material to be fluidised so as to flow in an orderly fashion. The apparatus shown here is designed for use with a finely divided somewhat powdery filtering material 7. The hopper chute 6 terminates somewhat above the bed 1 and is located between the two runs of a chain 8 carried on sprocket wheels 9 to move in synchronism with the garniture tape 3. The chain 8 has a series of links 10 each of which is transversely apertured to define a funnel 11 through which powder 7 can be conveyed into one of the spaces between the stubs 5. The links are recessed so as to accommodate the mouth of the chute 6, and are positioned and arranged to register closely therewith. Each link at its lower end is provided with side cheeks 12 which extend downwardly between the upper edges of the paper web 4 to guide the filtering material 7 into spaces between the stubs 5. The upper ends of the tunnels are somewhat downstream of the lower ends and the downstream face 11a of a funnel slopes downwardly and rearwardly as shown. This is to offset the dilterence between the speed of the falling powder 7 and the probable faster speed of the funnel. The object is to collect the appropriate quantity of powder cleanly with the minimum of disturbance, and so permit the powder to fall with the least interference evenly into the relevant space between the stubs 5.

The links 10 are designed so as to fit closely together and so far as possible to ensure that once the material 7 has entered a particular funnel it goes only into the respective space between the plugs associated with that particular funnel.

The plugs are formed somewhat larger than is required, and the shape of the trough 2 is such as to deform the plugs somewhat so as to increase the volume of the space between the plugs which can be filled without undue risk of material becoming trapped around a stub, where it could cause a by-pass, and subsequently when the paper 2 is wrapped around the stubs 5 and the pockets of material 7, the plugs are compressed and allowed to adopt a normal circular cross section. Details of this are described more fully in the previously referred to patent application.

The chain 8 is advanced at the same speed as the garniture tape 3 and each funnel 11 passes beneath the mouth of the chute 6 so it receives filtering material 7 at a steady rate throughout the whole time that it is under the chute 6. Thus the amount of material it receives is determined by its speed of travel, by the rate of feed of the material 7 and by the length of the mouth of the chute 6. Thus it is possible to vary the quantity of material which enters the funnel 11 and thus the quantity which goes into each space between the stubs 5 by changing any one of these parameters, either for dilferent diameters of the filter rod to be formed, for different lengths of the spaces between the stubs, or for different degrees of packing of the material within the spaces.

FIGS. 4-6

The embodiment of FIGS. 4 to 6 is generally similar to that of FIGS. 1 to 3 and corresponding parts have been given the same references. The difference here is that instead of a chain there is provided an apertured belt 18 which acts as a screen and serves to direct the material 7 into the spaces between the stubs 5 rather than on to the stubs. Downstream of the chute 6 there are provided ploughs 13 to sweep any excess material 7 oil the belt 18 through the relevant aperture and into the appropriate space between the stubs 5. The region in- 4 cluding the ploughs 13 and the chute 6 is surrounded by a guard 14.

FIGS. 7 and 8 Filter plugs 1111 are carried, spaced apart endwise, on a paper wrapper web 102, which is curved to U crosssection about the plugs as best seen in FIG. 8. The plugs are, as disclosed in the mentioned application, over-sized in cross-section and will subsequently be compressed when the rod is finally formed; and they are also deformed from cylindrical shape in the manner disclosed in the mentioned application. These plugs are conveyed past and beneath a chute 103 extending lengthwise over a number of plugs; loose material is fed into the chute, as will be described later, to fall through the chute as a shower.

The shower is intercepted by a screening element consisting of a series of funnelled guide elements 104 which form connected links of an endless chain passing over sprocket wheels 105 (only one of which is shown) the chute being disposed between the upper and lower runs of the chain so that the elements 104 forming the lower run intercept the shower. Each of these elements 194 is formed as an individual funnel having a wide upper receiving aperture 106 and converging to a narrower lower discharge aperture 107. As shown in FIG. 7, each element 104 straddles two plugs with its discharge aperture 107 coinciding with the gap between the plugs. The extremities of the funnelled elements 104 are shaped to conform with the curved surfaces of the plugs and engage with them inside the upstanding walls of the U-shaped wrapper web as seen in FIG. 8.

As shown in FIG. 7, the upper parts of the guide elements 1'64 cooperate with each other by engagement of an extension 108 formed on one element with a part 109 of the next succeeding element; thus the extension 108 of one element forms part of the funnel of the next surrounding element, in the region of the receiving aperture 106.

As the guide elements and plugs pass beneath the chute 193, the showered loose material is guided by successive funnels into the spaces between the plugs and the spaces are progressively charged with loose material.

Referring now particularly to FIG. 8, the bulk supply of loose material is contained in a conical hopper 110 which has at its base a tubular discharge funnel 111. The hopper is mounted above a vibrating conveyor 112 having side walls 113 and a top closure wall 114 which is apertured at 115 to admit the discharge funnel 111, the latter being located with its open mouth close to the conveyor 112. The conveyor 112 is mounted on leaf springs 116 and vibratory motion is imparted to it by an eccentric 117 and link 118. The precise location of the discharge funnel in relation to the conveyor 112 can be adjusted according to the depth of loose material required to be conveyed on the conveyor 112, the rate of supply to the conveyor being self-regulating in that the material can flow from the funnel 111 only at the rate at which it is fed away by the conveyor 112. Thus if the apparatus is stopped and the conveyor ceases to operate, no material flows from the hopper until the conveyor starts again.

At the discharge end of the vibrating conveyor 112 is mounted a metering gate 119, whose position can be adjusted by an adjusting screw 120, and whose lower edge is at a required distance above the conveyor 112 to meter the loose material and allow only the required amount to be discharged into the chute 103 which is positioned to receive it.

It will be seen that the quantity of loose material fed into a space between two plugs can be regulated by adjustment of the gate 119 and if necessary of the position of the funnel 111. In addition, of course, this quantity will depend on the speed at which the plugs, with their associated guide elements 104, move through the shower, and on the length (considered in the direction of movement of the plugs) of the chute 103.

When the plugs have passed beneath the shower and the spaces between them have received their complement of loose material, the plugs are compressed and the wrapper is folded about them and about the loose material in the manner disclosed in the two previously referred to patent applications to form a continuous complete rod. This rod is cut at suitable intervals through plugs to provide multiple-length filters for use in making filter cigarettes.

It may in some cases be desired to feed a mixture of two or more kinds of loose material into each space between two plugs; for example one material may be of a powdery nature while another takes the form of relatively coarse granules or crystals, the two kinds of material having different filtering properties. Another possibility is to feed expansible elements such as polystyrene beads to be contained between plugs together with loose material; these elements expand on heating and pack the loose material closer, thus ensuring that smoke passes through the filtering material. Or it may be desired to include small liquid-containing capsules together with loose material between the plugs, such for example as crushable capsules containing liquid fiavouring or other material.

In any such case it is possible simply to feed the two or more different kinds of material, or the loose material H together with other elements such as mentioned above, as a mixture from a common hopper. It may, however be considered desirable to control the proportions of the dilferent materials or of the loose material and other elements to be contained between two plugs, and in that case the apparatus above described can be modified by providing an additional hopper or additional hoppers as required, and directing a metered flow of material or elements from each hopper so that the shower contains the various materials or elements in the desired proportion. Further, the fiow of different materials or elements can be so directed that they occur in different sections of the shower, considered in the direction of movement of the plugs; thus for example a flow of loose material could be divided into two branches, with an intermediate flow of, say, crystals or capsules between the two branches, in order to deposit the loose material in a lower and an upper layer between two plugs, with an intermediate layer of crystals or capsules, the proportions being regulated by metering the two flows.

I claim:

1. A method for manufacturing a continuous filter rod, to provide filters containing loose material for cigarettes or other smokable articles, comprising forming a continuously moving trough of wrapping material, providing stubs of porous filtering material at regular intervals along the trough and introducing controlled amounts of loose filtering material from a bulk supply of such material into the spaces between the plugs, including dispensing the loose material continuously at a controlled rate onto a continuously moving apertured screen member which is moved in unison with the rod so that the screen member directs the fiow of loose material into each of the spaces in turn, the loose material being showered downwardly over a fixed length of the screen member embracing several apertures in the screen member at any one time so that the loose material falls through the said several apertures simultaneously as they pass beneath the showered material, in which the loose material is formed into the said shower by being vibrated on an inclined surface over one edge of which the material is allowed to drop.

2. Apparatus for depositing loose filter material into gaps between spaced apart filter plugs carried by a con- 'veyor, which comprises a screen which is moved in unison with the said conveyor, the screen having apertures in it which are in register with each of the said gaps between the filter plugs, and means to supply loose filter material into and through the said apertures so that the latter guide the loose material into the said gaps as the stream of plugs and screen move in unison, said last-named means being arranged to shower the loose material downwardly over a fixed length of the screen embracing several apertures in the screen at any one time so that the loose material falls through the said several apertures simultaneously as they pass beneath the showered material, in which the screen comprises a plurality of interconnected links shaped to form respective pockets for each of said gaps and being designed to receive predetermined volumes of loose filter material.

3. Apparatus for depositing loose filter material into gaps between spaced apart filter plugs carried by a conveyor, which comprises a screen which is moved in unison with the said conveyor, the screen having apertures in it which are in register with each of the said gaps between the filter plugs, and means to supply loose filter material into and through the said apertures so that the latter guide the loose material into the said gaps as the stream of plugs and screen move in unison, said last-named means being arranged to shower the loose material downwardly over a fixed length of the screen embracing several apertures in the screen at any one time so that the loose material falls through the said several apertures simultaneously as they pass beneath the showered material, comprising a chute through which the loose material is showered on to the screen, and a vibrating member located above the chute and adapted to have loose material deposited on it, the vibrating member being inclined so that when vibrating it causes the loose material to fall off one of its edges into the said chute as a shower.

4. A method as claimed in claim 1 in which the loose material is deposited onto the inclined surface by a chute.

5. Apparatus as claimed in claim 2 in which each pocket of the screen member has an inclined surface so that it forms a funnel by means of which the loose filter material is funneled into a gap between adjacent filter plugs.

6. Apparatus as claimed in claim 3 in which the loose material is supplied to the vibrating member through a second chute which terminates a short distance above the vibrating member so that the amount of loose material supplied by the second chute is determined by the rate at which the loose material falls off the vibrating member. 7. Apparatus as claimed in claim 6 in which the vibrating member is provided with a gate whose position above the said edge of the vibrating member is adjustable in order to control the rate at which the loose material can fall off the said edge.

8. Apparatus for supplying loose material which comprises a hopper connected to a chute which has an outlet spaced above a vibrator onto which loose material in the hopper can drop via the chute, the vibrator having an incllned surface along which the loose material from the chute will travel, in use, to an edge of the vibrator from which the loose material will drop as a shower.

9. Apparatus as claimed in claim 8 in which a gate is located adjacent the said edge, the gate being adjustable to vary the gap between itself and the inclined surface so as to control the rate of flow of loose material over the said edge of the vibrator.

References Cited UNITED STATES PATENTS 3,343,462 9/1967 Sexstone 93-1 3,367,245 2/1968 Wisdom 93-1 3,464,324 9/1969 Pinkham 93-1 3,482,488 12/1969 Sexstone 93--1 GRANVILLE Y. CUSTER, JR., Primary Examiner 

